HPAc Armourlite LTD test these bottles as i work there and i am the test engineer.Tel 01902 494988
tested every 5 years some of there newer bottles have a 30 year life all i say is to check before your buy as most of these are eating into there life span before you buy them.
FT is the best just forget the rest.
Rowan Engineering Team Member
MFTA Chairman/BFTA Rep
BFTA Trade Liaison Officer